Acesulfame potassium has an intense, sweet taste and has been used in many food-related applications as a sweetener. In conventional acesulfame potassium production processes, sulfamic acid and an amine, e.g., triethylamine, are reacted to form an amidosulfamic acid salt, such as a trialkyl ammonium amidosulfamic acid salt. The amidosulfamic acid salt is then reacted with diketene to form an acetoacetamide salt. The acetoacetamide salt may be cyclized, hydrolyzed, and neutralized to form acesulfame potassium. U.S. Pat. Nos. 5,744,010 and 9,024,016 disclose exemplary acesulfame potassium production processes.
Typically, the acetoacetamide salt intermediate is cyclized by reaction with sulfur trioxide in an inorganic or organic solvent to form a cyclic sulfur trioxide adduct. The solvent routinely utilized in this reaction is an organic solvent such as a halogenated, aliphatic hydrocarbon solvent, for example, dichloromethane. The adduct formed by this reaction is subsequently hydrolyzed and then neutralized with potassium hydroxide to form acesulfame potassium.
Acesulfame potassium product and the intermediate compositions produced by conventional methods contain undesirable impurities, such as acetoacetamide (and acetoacetamide-N-sulfonic acid). Limits for the content of various impurities are often set by governmental regulations or customer guidelines. Removal of many of these impurities using standard purification procedures such as evaporation, crystallization, and/or filtration has proven difficult, resulting in consumer dissatisfaction and the failure to meet standards.
The need exists for improved processes for producing high purity acesulfame potassium compositions in which the formation of impurities such as acetoacetamide during synthesis is reduced or eliminated.
All of the references discussed herein are hereby incorporated by reference.